Blender Git Loki

changes to relative path option
- initialize the relative_path option in ED_fileselect_get_params(), saves initializing within every operators own init functions, some even trying to initialize a non existing property.
- don't set the operator default from the user preferece, operator property defaults should be static else python scripts for eg can get different defaults depending on user settings, this also wont get updated when user-defaults are edited so generally confusing & not good practice.